Re: [Xen-devel] VT-d faults with Integrated Intel graphics on 4.6

["Chen, Tiejun" <tiejun.chen@xxxxxxxxx>]

On 8/25/2015 10:43 PM, Konrad Rzeszutek Wilk wrote:
> On Tue, Aug 25, 2015 at 02:55:31PM +0800, Chen, Tiejun wrote:
> > On 8/25/2015 8:19 AM, Tamas K Lengyel wrote:
> > >Hi everyone,
> > >I saw some people passingly mention this on the list before but just in
> > >case it has been missed, my serial is also being spammed with the following
> > >printouts with both Xen 4.6 RC1 and the latest staging build:
> > >
> > >...
> > >(XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr
> > >33487d7000, iommu reg = ffff82c000201000
> > >(XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set
> > >(XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr
> > >33487d7000, iommu reg = ffff82c000201000
> > >(XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set
> > >(XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr
> > >33487d7000, iommu reg = ffff82c000201000
> > >(XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set
> > >(XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr
> > >33487d7000, iommu reg = ffff82c000201000
> > >(XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set
> > >(XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr
> > >2610742000, iommu reg = ffff82c000201000
> > >(XEN) [VT-D]DMAR: reason 07 - Next page table ptr is invalid
> > >...
> > >
> >
> > What's your platform? BDW? And how much memory is set to your guest OS?
> Is see this as well. But oddly enough - only when I use the AMT feature
> (normally I just use serial console on the machine).
>
> The platform is             /DQ67SW, BIOS
> SWQ6710H.86A.0066.2012.1105.1504 11/05/2012
>
> There is no guest OS - this is initial domain. And I boot with 2GB:
>   Released 0 page(s)
>
> Xen: [mem 0x0000000000000000-0x0000000000099fff] usable
> Xen: [mem 0x000000000009a800-0x00000000000fffff] reserved
> Xen: [mem 0x0000000000100000-0x000000001fffffff] usable
> Xen: [mem 0x0000000020000000-0x00000000201fffff] reserved
> Xen: [mem 0x0000000020200000-0x000000003fffffff] usable
> Xen: [mem 0x0000000040000000-0x00000000401fffff] reserved
> Xen: [mem 0x0000000040200000-0x0000000080465fff] usable
> Xen: [mem 0x0000000080466000-0x000000009e855fff] unusable
> Xen: [mem 0x000000009e856000-0x000000009e85efff] ACPI data
> Xen: [mem 0x000000009e85f000-0x000000009e8a9fff] ACPI NVS
> Xen: [mem 0x000000009e8aa000-0x000000009e8b1fff] unusable
> Xen: [mem 0x000000009e8b2000-0x000000009e9a4fff] reserved
> Xen: [mem 0x000000009e9a5000-0x000000009e9a6fff] unusable
> Xen: [mem 0x000000009e9a7000-0x000000009ebc5fff] reserved
> Xen: [mem 0x000000009ebc6000-0x000000009ebc6fff] unusable
> Xen: [mem 0x000000009ebc7000-0x000000009ebd6fff] reserved
> Xen: [mem 0x000000009ebd7000-0x000000009ebf4fff] ACPI NVS
> Xen: [mem 0x000000009ebf5000-0x000000009ec18fff] reserved
> Xen: [mem 0x000000009ec19000-0x000000009ec5bfff] ACPI NVS
> Xen: [mem 0x000000009ec5c000-0x000000009ee7bfff] reserved
> Xen: [mem 0x000000009ee7c000-0x000000009effffff] unusable
> Xen: [mem 0x000000009f800000-0x00000000bf9fffff] reserved
> Xen: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
> Xen: [mem 0x00000000fed1c000-0x00000000fed3ffff] reserved
> Xen: [mem 0x00000000fed90000-0x00000000fed91fff] reserved
> Xen: [mem 0x00000000fee00000-0x00000000feefffff] reserved
> Xen: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
> Xen: [mem 0x0000000100000000-0x000000043e5fffff] unusable
>
> > Just at first glance to fault address, this seems be issued from some
As you see those fault addresses are out of the normal memory range  here.

> > known erratas on BDS and SKL.
> I am runnig v4.2-rc8.
So I really doubt this is related to some erratas. Currently the 
pre-fetch unit of IOMMU unit dedicated to IGD can't work well on some 
platforms, so you can see these wired faults.
Thanks
Tiejun

> > Thanks
> > Tiejun
> >
> > >The device in question is an integrated Intel graphics card:
> > >
> > >00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core
> > >Processor Family Integrated Graphics Controller (rev 09)
> Same device..
> > >
> > >The only way I found to stop the messages from making my serial connection
> > >useless was by assigning the device to xen-pciback.
> > >
> > >Cheers,
> > >Tamas
> > >
> > >
> > >
> > >_______________________________________________
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> > >Xen-devel@xxxxxxxxxxxxx
> > >http://lists.xen.org/xen-devel
> > >
> >
> > _______________________________________________
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